Arterial hypotension induced by horseradish peroxidase in various rat strains.Deimann, W; Taugner, R; Fahimi, H D
doi: 10.1177/24.12.1002975pmid: 1002975
The influence of various commercial preparations of horseradish peroxidase upon the arterial pressure has been investigated using direct intra-arterial pressure recordings in Nembutal anesthetized rats of different strains. A marked hypotension was noted in Wistar and Sprague-Dawley rats when sufficiently high doses (5-10 mg/100 g body weight) were injected intravenously. This effect was observed with both highly purified (Sigma type VI, Boehringer Reinheitsgrad I) as well as less pure preparations (Sigma type II, Boehringer Reinheitsgrad II). Prior injection of promethazin, an antihistamine, prevented the drop in arterial pressure. Wistar/Furth rats appeared almost resistant to the hypotensive effect of Sigma preparations but developed moderate to marked hypotension with both types of Boehringer horseradish peroxidase. When instead of Nembutal, ether anesthesia was used only a transient mild hypotension developed and the animals recovered within 7-10 min. No effect was noted in Syrian hamsters receiving injections with the same doses of horseradish peroxidase. Electrophoresis revealed marked variations in the isozyme composition of different horseradish peroxidase preparations. Since the exact nature of the hypotensive agent remains unknown, it is suggested that the arterial pressure be monitored before extensive systematic application of this tracer in vascular permeability studies in rats.
A new histochemical method for the identification and visualization of both side chain acylated and nonacylated sialic acids.Culling, C F; Reid, P E; Dunn, W L
doi: 10.1177/24.12.187689pmid: 187689
A new histochemical method is described for the differentiation of mucins that utilizes two different Schiff reagents and allows single section identification of side chain O-acylated, and nonacylated, sialic acids in contrasting colors. In the event of mucins containing only one type of sialic acid, it may allow their specific identification (e.g., C7 or C8 side chain O-acylated). It has been shown to be useful in the identification of some metastases from adenocarcinomas of colon (where the primary is potassium hydroxide/periodic acid-Schiff positive) and should prove of great value in the investigation of diseases of the gastrointestinal tract and particularly those of the colon. It should also be valuable in the general field of epithelial mucin histochemistry, particularly for those mucins of the salivary and parotid glands, etc.
Quantitation of mast cell heparin by flow cytofluorometry.Enerbäck, L; Berlin, G; Svensson, I; Rundquist, I
doi: 10.1177/24.12.63510pmid: 63510
Mast cells can be automatically identified in a mixed cell population by flow cytofluorometry after Berberine sulphate staining. Volume specific counts of the total number of cells and number of mast cells, as well as frequency distributions of fluorescence intensities of mast cells, based on a large number of cells, can be rapidly obtained. Results obtained by microscope fluorometry of cells identified by phase contrast microscopy showviously published results it may be inferred that the fluorescence intensity of individual mast cells is proportional to mast cell heparin content. The automated cell counts correlated very well with manual hemocytometer counts. Both cell counts and the determination of mean mast cell fluorescence showed excellent reproducibility.
Peroxisome development in the regenerating pars recta (P3 segment) of proximal tubules of the rat kidney.Reddy, J K; Rao, M S; Moody, D E; Qureshi, S A
doi: 10.1177/24.12.1002976pmid: 1002976
The development of peroxisomes, lysosomes and endocytic vacuoles in regenerating cells of the pars recta (P3 segment) of proximal tubules, in rats given a single interperitoneal injection of d-serine (80 mg/100 g.b.wt), was studied by light and electron microscopy using cytochemical methods. Rapid proliferation of cells occurred between 2 and 5 days after d-serine induced tubular necrosis; by day 6 almost all injured tubules were re-epithelialized with flat or low cuboidal cells. Peroxisomes and lysosomes were not observed during the period of rapid cell multiplication i.e., between 2 and 6 days after d-serine injection. Restitution of mitochondrial population preceded the development of peroxisomes in the newly regenerated cells of P3 tubules. Maximum development of peroxisomes occurred between 9 and 14 days after d-serine injection. The formation of peroxisomes appeared to correlate closely with the differentiation of apical endocytic vacuoles and the brush border. Lysosomes in the regenerated cells of P3 tubules were the last to develop.
Acrolein as a fixative for enzyme cytochemistry.Saito, T; Keino, H
doi: 10.1177/24.12.187691pmid: 187691
Since acrolein can penetrate more quickly and deeply into tissue blocks than glutaraldehyde, the possibility of the use of this aldehyde as a prefixative in enzyme cytochemistry was reinvestigated. At low concentrations, acrolein preserves the activities of the enzymes investigated, including those of glucose-6-phosphatase, which is known as one of the most vulnerable to aldehyde fixation; thus, acrolein is usable in enzyme ultracytochemistry. Enzyme activities are also preserved in tissues fixed with acrolein and glutaraldehyde combined. The rapid penetration of acrolein enables fixation in larger tissue blocks and provides greater freedom in specimen selection, especially important advantages when encountering heterogeneous materials as in pathology.
The blue reaction product in horseradish peroxidase neurohistochemistry: incubation parameters and visibility.Mesulam, M M
doi: 10.1177/24.12.63512pmid: 63512
A blue reaction product is formed at sites that contain horseradish peroxidase (HRP) activity when benzidene is used as the chromogen. With neutral red as a counter stain, this method affords excellent visualization of both retrograde and orthograde axonal transport of intracerebrally injected HRP. The visibility of this blue reaction-product is better than the visibility of the brown reaction-product obtained in the commonly used diaminobenzidene procedures. Variations in incubation times and reagent concentrations resulted in significant differences in the extent to which transported HRP could be demonstrated with benzidene. One of these benzidene procedures demonstrated a wider extent of HRP transport than a representative diaminobenzidene procedure. The substantia nigra and the nucleus locus ceruleus did not display artifactual deposition of the blue reaction-product.